Colourtone
Tony Gaukroger, Director at Colour Tone Masterbatch, discusses why end-of-life concerns for caps and closures have been put in the ‘spotlight’ as manufacturers adopt the How2Recycle label.
In August this year it was announced that the world’s largest bottled water company, Nestle, has started using the How2Recycle label on its half-litre bottles for major brands in the United States.
Its aim is to encourage and educate all Americans to recycle plastic bottles – by providing consumers with a clear and consistent message. Nestle is also encouraging other packaged goods makers to adopt the labelling standard created by the Sustainable Packaging Coalition in 2012.
This initiative means fewer loose caps will have the potential to get into waterways and oceans. It also helps to ensure that the caps will be recycled, with caps being replaced they can then go through the recycling stream and are therefore, less likely to fall through a recycler’s equipment – so far, so good.
It will no doubt lead to the capture of far higher volumes of bottle caps for the first time, which means more of this valuable resource which can be turned into something else.
But this poses yet another challenge, if other bottled water and soft drinks makers adopt this labelling scheme, are they confident that the caps it has been designed to capture can be effectively recycled?
Water bottles are moulded predominantly with clear PET, yet the caps are manufactured either in black, or, an increasing myriad of coloured PE material. The separation of this plastics waste stream therefore, remains a problematic issue, since not only black, but some coloured bottle caps, can absorb infrared – which renders them ‘invisible’ to near infrared sorting systems used by recyclers – so they end up in landfill instead.
Near infrared red pigment technology
The problem of recycling black plastics has been well documented recently. As a specialist, additive and masterbatch manufacturer, Colour Tone has spearheaded research into the problem of how to recycle black plastics packaging through the development of novel near infrared (NIR) pigment technology.
This pigment enables black plastic to be visible for NIR sorting. It has proved in numerous materials validation trials with black food trays and tubs that this colourant does not inhibit the sorting of the mixed plastics waste stream when sorting with NIR spectrophotometers.
But most importantly, this technology can be applied to coloured plastics too, since they also contain IR absorbing pigments, allowing colours to be specified with the same NIR sorting characteristic.
If manufacturers are serious about ‘closing the loop’ on water and soft drinks bottles finally, they must rethink the materials selection for caps and closure design too. While plastic bottles have come a long way when it comes to recycling in recent years, it seems that there is still much room for improvement.
Britain alone consumes £3bn litres of bottled water per year and it’s the fastest growing drinks market in the world – that’s a lot of caps.